File forwarding capacity is the maximum rate per minute at which each Palo Alto Networks firewall platform can submit files to the WildFire cloud or a WF-500 appliance for analysis. If the firewall reaches the per-minute limit, it queues any remaining samples.
The Reserved Drive Space column in the following table lists the amount of drive space on the firewall that is reserved for queuing files. If the firewall reaches the drive space limit, it cancels forwarding of new files to WildFire until more space in the queue is available.
The speed at which the firewall can forward files to WildFire also depends on the bandwidth of the upload link to the WildFire systems.